1. Field of the Invention
The present invention relates to a malfunctional detecting apparatus for an assist air control system for internal combustion engines.
2. Description of the Related Art
In a conventional type of fuel injection system for internal combustion engines, the assist air is jetted against fuel to be injected in order to facilitate the atomization of the fuel, and a device for judging malfunction in this fuel injection system has been disclosed in the Japanese Examined Utility Model Publication No. 4-55255. In this malfunctional judging device, a first pressure sensor for detecting the pressure in an intake passage and a second pressure sensor for detecting the pressure in an air introduction passage are provided, and malfunction is judged when the difference in pressure between the intake passage and air introduction passage detected by the first and second pressure sensors respectively is more than the predetermined value.
For the above malfunctional detecting device for the fuel injection system for internal combustion engines, it is necessary to secure a sufficiently high response of a control valve installed in the air introduction passage. However, such malfunctional judgment, i.e., whether the response of the control valve is sufficient or not, is not performed.